Carbon nanodots and zinc oxide nanoparticles coated fabrics as effective photocatalytic materials for water treatment

Abstract

Carbon nanodots (CNDs) derived from steam-activated date palm fronds and zinc oxide nanoparticles (ZnO NPs) synthesized via a bio-assisted sonochemical method were coated onto a textile material and used as photocatalysts for the effective removal of methylene blue (MB) from wastewater. Characterization techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), spectral fluorophotometry, and other related techniques, were employed to investigate the morphology, photoluminescence (PL) emission, band gap energy, phase composition, and surface wetting behaviour of the prepared samples. The photocatalytic experiments were carried out under four different light conditions, namely sunlight, visible light, UV-radiation, and darkness. The experimental findings indicate that both CNDs- and ZnO-coated fabrics degrade MB more efficiently under UV-radiation, achieving high removal efficiencies exceeding 90 and 60%, respectively, within 40 and 60 min, while also exhibiting substantial activity under sunlight and visible light at low initial MB concentrations. Overall, this study demonstrates the great potential of these materials for practical wastewater treatment and self-cleaning textile applications. Furthermore, the immobilization of CNDs and ZnO NPs onto fabrics reduces concerns regarding the reuse and recovery of the photocatalyst materials while maintaining high photocatalytic efficiency.

Graphical abstract